Seiko D-1 Instructions Manual page 38

３）Pull the pin out of a adjustment hole
of the band. Slide the band to adjust
its length and find an appropriate
hole. Place the pin into the hole.
Pin
Adjustment hole
72
４）Fasten the buckle with pressing the
push buttons.
C Type
１）Press the button on the buckle, and
lift to open the clasp.
Push button
２）To adjust : Pull the pins out of the
adjustment holes on the band. Slide
the band to the appropriate length.
Push the pins into the new holes on
the band.
Adjustment hole
Pin
73